Math people, quick questions

[Iwinyourmoney]

Real quick question.

Ill make this simple.

You have 20 envolopes to chose from.
(3) envolopes each have a value of 0
(17) envolopes each have a value of 1

What are the odds to pick the (3) envolopes that hold 0 without picking an envolope that holds a 1

[pico]

off top of my head (3/20)(2/19)(1/18)=0.09%

could be wrong.

[HedgeHog]

one chance in 1140. Or 1139 to 1 as fair odds.

PS Same answer as Pico, but put a different way.

[Justin7]

Picoman is correct.